The eighteenth and nineteenth centuries are sometimes called the "age of transition" because the world was moving toward a global economy. This was in large part due to the widespread availability of intercontinental travel and warfare using massive sea vessels. It was the era when European powers took to the seas to consolidate (and often lose) their control over colonies in Asia, Africa, and the Americas. It was also a time of ocean wars, rapid advances in shipping technology, and global trade on a scale never witnessed by humans before. That's why Princeton historian Ben Schmidt's visualization of all the shipping routes taken by Dutch, Spanish, and English vessels is completely fascinating. You can actually see history unfolding in this record of where the Europeans were going and when.

Schmidt explains the top video (which you should really watch at a larger size):

It shows about 100 years of ship paths in the seas, as recorded in hundreds of ship's log books, by hand, one or several times a day. I haven't watched the whole thing at once, but skipping around gives a pretty good idea of the state of the database (if not world shipping) at any given moment. This shows mostly Spanish, Dutch, and English routes—they are surprisingly constant over the period (although some empires drop in and out of the record), but the individual voyages are fun. And there are some macro patterns—the move of British trade towards India, the effect of the American Revolution and the Napoleonic Wars, and so on.

It's incredible that we have such detailed records of European trade and expansion from 250 years ago.

Schmidt also wanted to explore how seasonality affected shipping, so he compressed all the data you see above into a video that shows 100 years as if they were one year, giving us a sense of how trade routes varied by seasons. He writes:

There aren't many truly seasonal events, but a few stand out. There are regular summer voyages from Scotland to Hudson's Bay, and from Holland up towards Spitsbergen, for example: both these appear as huge convoys moving in sync. (What were those about?) Trips around Cape Horn, on the other hand, are extremely rare in July and August. More interestingly, the winds in the Arabian sea seem to shift directions in November or so. I also really like the way this one brings across the conveyor belt nature of trade with the East.